Restore wordsize methods and constant as deprecated

These were removed by CRuby but that breaks running older rubyspec
with new mspec. We restore them here while the change propagates
into rubyspec.

lib/mspec/guards/platform.rb

@@ -53,6 +53,9 @@ def self.wsl?
     end
   end
 
+  WORD_SIZE = 1.size * 8
+  deprecate_constant :WORD_SIZE
+
   POINTER_SIZE = begin
     require 'rbconfig/sizeof'
     RbConfig::SIZEOF["void*"] * 8
@@ -66,6 +69,11 @@ def self.wsl?
     [0].pack('l!').size
   end
 
+  def self.wordsize?(size)
+    warn "#wordsize? is deprecated, use #c_long_size?"
+    size == WORD_SIZE
+  end
+
   def self.pointer_size?(size)
     size == POINTER_SIZE
   end
@@ -91,6 +99,9 @@ def match?
         match &&= PlatformGuard.os?(*value)
       when :pointer_size
         match &&= PlatformGuard.pointer_size? value
+      when :wordsize
+        warn ":wordsize is deprecated, use :c_long_size"
+        match &&= PlatformGuard.wordsize? value
       when :c_long_size
         match &&= PlatformGuard::c_long_size? value
       end